LOWELL -- Democrats from around Massachusetts convened in Lowell on Saturday, emboldened by a streak of election wins and looking ahead to next year's wide open contest for governor.

"From what I can see, we have a good field of candidates," said E. Henry Twiggs, chairman of the Springfield Democratic City Committee and a delegate at the party's platform convention, held at the Paul Tsongas Center at the University of Massachusetts at Lowell. "There are so many good candidates."

Treasurer Steven Grossman, shown at the state Democratic convention in Lowell, told reporters that he is a candidate for governor in next year's election.Dan Ring/The Republican

The issues convention came just about a few weeks after Edward J. Markey won a U.S. Senate special election on June 25 to fill the unexpired term of Secretary of State John F. Kerry.

Three declared candidates for governor -- Donald Berwick of Newton, former administrator of the federal Centers for Medicare and Medicaid Services, state Sen. Daniel Wolf of Harwich, and physician Joseph Avellone of Wellesley -- gave speeches.

Treasurer Steven Grossman used the convention to tell reporters that he definitely will be a candidate for governor next year to replace Gov. Deval L. Patrick, a two-term Democrat who is not running for re-election.

"I am running for governor of Massachusetts," Grossman said after his convention speech. "I think that was clear. If it wasn't, I will make it clear. It's a campaign that will be about leadership that leaves no one behind."

Grossman would be the third state treasurer to recently seek the governor's job. Shannon O'Brien lost in 2002 in the general election to W. Mitt Romney and Timothy Cahill finished third in 2010, far behind the GOP nominee and Patrick.

"I think I bring a fundamentally different set of skills and a fundamentally different set of lifetime experiences," said Grossman, who for 35 years was president of a fourth-generation, family-owned business now called Grossman Marketing Group in Somerville.

Gov. Deval Patrick, on the left, was introduced at Saturday's state Democratic convention by John Walsh, chairman of the state Democratic party.Dan Ring/The Republican

Grossman emphasized that he supports a bill to require businesses to offer paid family sick leave and would push for that bill as governor.

Grossman supporters wore orange t-shirts to stand out on the convention floor.

"I like what he stands for," said Jeanne Pryor, chair of the Becket Select Board who is backing Grossman.

During her speech, Attorney General Martha Coakley made no mention of her possible candidacy for governor. Her supporters, however, showed up in force with signs outside the convention center.

“I know there’s a lot of people making announcements today. I have one, too: Tomorrow is my 60th birthday,” Coakley said during her speech.

Coakley said she was at the convention to celebrate with fellow Democrats about all the progress made so far including a U.S. Supreme Court ruling last month that legally married same-sex couples should be entitled to the same federal benefits as heterosexual couples. Coakley had filed a lawsuit to challenge the federal law that denied those benefits to gay couples.

Coakley said she is considering a run for governor but might also run for a third term as attorney general.

Energy and Environmental Affairs Secretary Richard K. Sullivan Jr. of Westfield was at the convention on Friday night and Saturday.

In an interview, Sullivan, former mayor of Westfield, said he now is only looking at a possible bid for lieutenant governor, not governor or treasurer.

“The conversations were good,” Sullivan said after speaking with delegates. “People were very kind with their time and opinion.”

Other possible Democratic candidates for governor include U.S. Rep. Michael Capuano of Somerville and Juliette Kayyem, former Massachusetts homeland security undersecretary.

Possible Republican candidates include former U.S. Sen. Scott Brown, Charles Baker, the party's nominee for governor in 2010 and Gabriel Gomez, the Republican nominee in last month's Senate special election.

Delegates said they are aware that Republicans held the governor's seat for 16 years before Patrick was elected.

Brown defeated Coakley in a 2010 U.S. Senate special election before he was defeated for re-election in November by U.S. Sen. Elizabeth Warren, a Democrat.

Twiggs and many other Democratic delegates from Western Massachusetts said they are still making up their minds about which candidate to support for governor.

"I definitely have some research to do," said Brenna Murphy McGee, a city councilor in Holyoke. "At this point, they are all on an equal playing field."

"I have to see who is truly behind what I believe in," added Laurie Garcia of Easthampton, who teaches Spanish at the Amherst Regional Middle School.

"A Democrat will keep the seat," said Gillian Hinkson of Springfield, who is on the support staff for the Hampden district attorney. "I'm confident of that."

In his speech, Berwick said he is "an improver," and an optimist with a track record of making government work for people.

"I want to see Massachusetts become the beacon the country needs," he said.

Berwick talked about how President Barack Obama named him administrator of the Centers for Medicare and Medicaid Services in July 2010 as a temporary "recess appointment."

Berwick said he stepped down in the face of a possible Republican filibuster to prevent a longer tenure for him.

Avellone, a surgeon and former Wellesley selectman, told delegates that the state is at a crossroads and needs to build a new economy for the 21st century.

"We can't create new jobs with business as usual. It will take .. bold ideas," said Avellone, a senior vice president at Parexel International Corp., a biopharmaceutical services company.

Avellone said controlling health care costs is critical, saying the costs are squeezing families and businesses. He said the next governor needs to work with health care leaders to change the way health care works.

Wolf, a two-term state senator, spoke about his success in building Cape Air into one of the largest independent airlines in the nation. Wolf was a co-founder of the airline that became Cape Air.

In his speech, Wolf talked about his support for issues such as making college more accessible and affordable, clean energy, organized labor and more economic justice for the middle class.

"I'm very concerned we have an economy now that is working well for a small number of people but really isn't working well for the majority of people," Wolf said in an interview. "I am running for governor to try to work hard to get an economy that really supports ... the middle class."